How to search files from windows command prompt

I am still struggling with yesterday problem in my docker. I can't find the file docker.qcow2 in my windows env but some gain additional information on how to search a file from windows command prompt.

type below to go to your main directory c:
cd c/ 

then
dir secret.doc /s /p

Reference:
http://www.dummies.com/computers/operating-systems/windows-xp-vista/how-to-search-for-files-from-the-dos-command-prompt/